What is a horses rectal temperature supposed to be?

This question is WAY to general, as horses live all over the worl, so lets say anywhere from -20 F. to 120 f.

As a treet only, There is A lot of sugar in most cereals, Also there may be other substances in them that horses digestive system may not tollerate too well.

In the hind hole. But to make sure check with a doctor or vet

Horses are very good at adapting to temperatures. They can withstand very cold weather, and some pretty hot temperatures too. They do stand cold better though. Provided you leave them naturally with...

Normal Temperature = 99.5-101.3°F or 37.5-38.5° CRemember that physical work and stress change body temperatures.